Process of forming a spirally-wound tube.



G. T. PRATT. PROCESS OF FORMING A SPIRALLY WOUND TUBE. APPLICATION FILED D30. 6, 1909.

1,046,85 1 Patented Dec. 10, 1912.

2 SHEETkSHEF-T 1.

INVENTUR CHARLES 1: PRATT ATTORNEYS G. T. PRATT. PROCESS OF FORMING A SPIRALLY WOUND TUBE.

APPLICATION FILED 1120.6, 1909. I

Patented Dec. 10, 1912.

' 2 SHEETS-SHEET 2.

WITNESSES: S INVENTOR 0 L55 '7. PRATT Mug ho o'H-An Esa. rnar r-,-r or F h-ANKF O RT, new Y oRKif citizen off-the United-States, residing atioaassr;

' rnoons's or FORMIN ;sPiR LLir-woom) irUBE.

o alll'whom 'it may'concem:

'Be it known that-"I, C ARLES' T. l n;rr'r; a.

Frankfort, 'in the, county of Herkimer and State of New York, have. invented certain new and useful Improvements in Processes .of Forming a SpiraHy-Vound Tube, of which thefollowing is a specification, refer= ence being had therein to the accompanying drawing.

'My -invention relates to an improvement in the process of forming a spirally wound -t'ube,' .and I 'declare that the following is 'a full, clear,

concise and exact description thereof, sufficient to enable one sKilled in the art to make and use the same, reference be ing had to the accompanying drawings in 'whic-h'like reference oharacters refer to like parts throughout. 1

'In the manufacture of suchtubing, either. in the formto produce a tube orto. form-an "armor about a cable, astrip is Wound sp.i-

are sometimes cross section so that when wound one rally with overlapping coils. Such strips given an. ssshape in edge will be-of smaller diameter than the other sot-hat. the succeeding coil will overlap-the former. In the straightstrip or ribbonof such metal, with any variety of form in cros's'section, one edge is of equal length with theother; and if the strip be wound in a'spiral wit-h one edge overlapping another the product-will not'be of the same diameter from end to end. In other words, it is necessary'that the edge which i's'to'be covered by .the overlapping and succeeding edge should .be reduced or contracted.

The devicewhich I illustrate in the ac companying drawings is one which is suitable for use in reducing one edge of the metallic strip or ribbon as. it is fed through the machine.

In the drawings Figurel shows the parts -which make up the die of such machine, the

View being perspective from one side and the parts being separated. Fig. 2 is a vertical sectional view of the die on the line 22 of 1, the grooving wheel and stud being removed and shown in full lines. Fig. "3 is a perspective view from the side oppo- .site to that-given in Fig. 1, with parts broken away. Fig. 4. is a sectional view on theline of Fig. 1. Fig. 5 shows a portion of theribbon and the coil. Fig. (3 is a fragmentary plan View, somewhat en- Specifieatien of Letters iatent.

Application. filed. Decemberfi, iaeefiseriai No. 531,473.

shown inlfull'; Fig. 8 is-a fragmentary view in side-elevation'of the d e.

It will be understood that this-die may be used in any .suitable machine which c'omprises means for forcing the ribbon into the die. The formation of; the die is such that the ribbon fed into itdisguided with oneedge against the end of'the guiding stud f atented pas. 101, 11912;;

.largedof-tne die; Fig. 7, is a seotion 'enlarged taken online 7-7 of Fig.1, parts wherebyas it is pressedthrough the die it isfed out of the' die inspir'al form. The die is madeof a suitable block 1 with a transv v verse bore shown at 2 into which opens the ideway shown at 3. "The guideway is formed with di-flerentlevels, shown at 5 and a 6, with theshoulder 7 between, which shoulder forms a" ridge passing along the guideway andbbliquelythereof to the transverse bore and around the same in a continuous spiral. wind. A portion of the ribbon 9 and coil 10 produced is shown in Fig. 5. .As the ribbon isffed in, the portion which is shown" as hollowed, 11, rideson the upper elevaand around the same being .large enough,=:'as indicated at 17, to allow-for the fullness of the ribbon where it has the outward curve and for the greater diameter of the tube. between the points where one coil overlaps the other. 'A; cqil cannot, however, be formed with spirally-wound overlapping folds of an equal diameter throughout unless one edge of the ribbon be bent inwardly. To ac'com-. plish this result-'1 provide a. wheel 20 having partof its .periphery.' asat. 21, of curved formation, the rest of the peripherv being plane, as at 22, a peripheral groove 2%) be ng provided between the two portions into which the edge of the ribbon passes from I the guiding stud. This wheel is mounted on a stud' 25 which is obliquely supported in the block 1, as in the bore 26, so that the wheel 20 has the same alinement as the. spiral. twist in the die. It'will be under;

stood, of course, that the die is cut out, as

at 29, to receive thez'wheel. The stud 4 is mounted on a'block 4: which is a component art of the block 1 and substantially fills the ore 2 diametrically, leaving space between the wheel 20-and the stud forthe passage of the ribbon, the stud-being slightly flattened or reduced, as at 4:", to allow space for the A ribbon. The plate or block 4" is held on the blockl by bolts or other suitablemeans. The .ribbon or strip being bent inwardly. into the die and being guided by the guides therein is brought. with one face, the portion indicated at 11, Fig. 5, to bear against the part 21 of the wheel which, as it revolves, pressesconstantly against the ribbon along that portion thereof and compresses or bends inwardly portion 11 of said. coil whereby the next succeeding spiraloverlaps to produce the tube shown in Fig. 5. While the wheel is shownas being of a uniform periphery it may be transversely notched or corrugated so as to-eifect a series of successive pressures instead of a continuous pressure, without-departure from the spirit and scope of the invention which, briefly stated, is the process of ceiling a ribbon with its edge overlapping in spirals and bent inwardly on the'edge of the ribbon to allow for theoverlapping.

- The stud 4 is shown as having a bolt 40 and as being slotted with the bolt therethrough. -This constructionis not exclusive of otherjforms however, for the stud may be shown as of acollar-form axially, leaving enough edge to guide the ribbon but having a bore for the passage of a Wire or cable around which it may be desired" to on so as to bend one edge thereof inwardly,

substantially as described.

2. The herein described process of coiling a metallic ribbon upon itself in a tube,

which consists" of forcing; the ribbon through a 'die'a'nd'in 'its'passage through' applying pressure thereon so as to bend one edgethereof inwardly, the opposite edge of the ribbon being convexed ,in cross section .to overlap the bent edge and compressed into close contact therewith, substantially as .ds'cribed.

3. The herein described process of coilinga metallic ribbon upon. itself into a tube which consists in forming the ribbon on its inner 'face into compound curvesin crosssection and bending one edge of the ribbon inwardly for permitting the concaved portion to. overlap the inwardly bent portion,

substantially .as set forth. I p In testimony whereof I hereunto 'my signature in the presence of two witnesses.

CHARLES T. PRATT.

Witnesses: I

EntANoR' T. DE Groeor, T-. L. Wrwna. 

